There is something you can do. To file a case against that person, you need an evidence that the person owes certain amount and he denies to pay it back to you. So, text the person saying "Hey Ramesh, you owe my $5000, when are you going to pay me back"? Then ask him, "Are you going to pay my $5000 or not"? If he says, "No", then you have a case. It doesn't matter if you have proof that you gave that person money. You need proof that the person denies to return your money, then you have a case. Go to a local police station with the printout of text, and ask how you can file a case against that person. They will help you there. Good luck and hope you get your money back!